#include<stdio.h>
#define NUM 8
int a[NUM+1];
int main(int argc, char const *argv[])
{
    int number,i,k,flag,not_finish=1,count=0;
    i=1;
    a[1]=1;
    printf("The possible configuration of 8 queens are:\n");
    while (not_finish)
    {
        while (not_finish&&i<=NUM)
        {
            for(flag=1,k=1;flag&&k<i;k++)
                if(a[k]==a[i])
                    flag=0;
            for(k=1;flag&&k<i;k++)
                if((a[i]=a[k]-(k-i))||(a[i]==a[k]+(k-i)))
                    flag=0;
                if(!flag)
                {
                    if(a[i]==a[i-1])
                    {
                        i--;
                        if(i>1&&a[i]==NUM)
                            a[i]=1;
                        else if(i==1&&a[i]==NUM)
                            not_finish=0;
                        else 
                        a[i]++;
                    }
                    else if(a[i]==NUM)
                    a[i]=1;
                    else
                        a[i]++;
                }
                else if(++i<=NUM)
                    if(a[i-1]==NUM)
                    a[i]=1;
                    else
                    a[i]=a[i-1]+1;
        }
        if(not_finish)
        {
            ++count;
            printf((count-1)%3?"[%2d]:":"\n[%2d]:",count);
            for(k=1;k<=NUM;k++)
                printf(" %d",a[k]);
                if(a[NUM-1]<NUM)
                    a[NUM-1]++;
                else
                    a[NUM-1]=1;
                    i=NUM-1;
        }
        
    }
    
    return 0;
}
